Coring device



May 8, 1928.7

F. C. MERRITT CORING DEVICE 'rTolaA/sy Patented `May s, 192s.

UNITED STATE-S PATENT OFFICE.

FLOYD C. MEBRITT, OF- LOS ANGELES, CALIFORNIA, ASSIGNOR TO ELLIOTTCORE DRILLING COMPANY, A CORPORATION 0F CALIFORNIA.

GOBING DEVICE.

Application tiled August 31, 1927. Serial No. 216,585.

My invention relates to the art oftaking cores during the o eration of drilling oil wells and the like, ing more particularly a device for relieving pressure in the inner core barrel above the core being taken.,

In taking cores by the rotary method of drilling, it is common practice to use a flushing luid ejected from the drill into the hole approximately at the cutting level of the lo drill, consequently the bottom of the hole is filled with mud formed Iby the mixing of this fluid with the cuttings from the formation. The core drills are frequently pulled from the hole and, upon lowering the same I6 into the hole the core barrel, being open at the bottom, fills vup with the mud or other accumulation in the` hole. ,Usually the core barrel is equipped at its upper end with a valve'which opens against the pressure of the flushing Huid, to ermit the mud in the barrel to be displace by the core being formed, but this is objectionable as it retards the movement of the core into the barrel and consequently results in the necessity of a $5 longer operation in obtaining the core.

One of the principal objects of my in-4 vention is to produce a device of the class described, wherein a packing element is interposedin the fluid passage between the in- 3" nei' and outer barrel of a double barrel `core drill, so that the downward current of {lushing fluid is directed about discharge openings of the inner barrel.

Other objects and advantages will appear '35 hereinafter from the Ifollowing description and drawings.

Referring to the drawings which are for illustrative purposes only,

Fig. 1 is a vertical sectional view through a portion of a double barrel core drill, em-

bodying a form of my invention.

Fig. 2 is sectional plan view on line 2-2 of 1, and ig. 3 is a vertical sectional view, similar to Fig. 1 on a smaller scale, showing the parts of the drill in assembled position.

More particularly describing the form of my invention shown in the drawings, 10 designates the outer barrel of a double bar# rel core drill made of whatl is commonly termed upset pipe, that is pipe of increased thickness at each end, or threaded portions of' the pipe as indicated at 11. The barrel 10 is threaded at its lower end into a cutter head 12 which may be of any vpreferred construct-ion provided the saine is formed with outlet or discharge openings 13, which comlnunicate with the annular space 14 or fluid passage between the outer barrel 10 and the inner or core barrel 15.

It is to be understood that the upper `end of the barrel 10 is connected, by means of a tool joint 16 or other coupling member, to the drilling string (notshown).

The inner barrel 15 is threaded at its lower end with the cutter head 12, the opening in the core barrel 15 registering with a core receiving opening 17 in the cutter head.

In the form shown, the upper end of the inner barrel 15 is threaded with a reducing nipple 18 which receives a hollow stem 19 threaded thereinto, the upper end of the stem 19 terminates in a reduced threaded end 20, forming a shoulder 21 upon which is seated a circular head 22, provided in the forni shown with two discharge openings 23, the inner walls of which converge downwardly as shown in Fig. 1.

The head 2 2 is centrally apertured to receive a valve casing 24 threaded at its lower end to the upper end 2O of the stem 19, the end of the stem forming a valve seat for a ball valve 27.

The valve casing 24 is provided with two discharge nozzles 30, oppositely disposed and extending outwardly and downwardly into the discharge openings 23. p The operation of the device, as above described, is `as follows; flushing or circulating fluid under pressure is caused to flow downwardly from the outer barrel, above the inner barrel into the annular passage 14.- between the barrels and being finally discharged through `the discharge outlets 13 in the cutter head.

This fluid, flowing under pressure through the openings 23 in the plate 22, causes a suction in the discharge nozzles 30,.thereby as sisting in lifting the ball 27 and causing the mud and accumulation in the inner barrel above the core to .be discharged through the valve and discharge nozzles.

The device as above described, is efiicient when the inner surface of the outer barrel is smooth in bore, and the outer edge of the head 22 may be made slightly smaller than the inside bore of the outer barrel, but when upset pipe is used for the outer barrel, such as I have referred to above, the head must be made with a small enough diameter to pass the upset portion of the pipe and when the inner barrel is finally connected to the cutter head, as shown in Fig. 3, a considerable space is left between the head and outer barrel, allowing the greater part of 4 the Huid to pass downwardly without passing through the openings in the head 22 resulting in an impairing of the function of such openings and the discharge nozzles therein.

To overcome this objection, I provide a packer consisting of a circular section or collar 32 of rubber composition or other suitable elastic or flexible material fastened at its lower end to a flange 33 on the head 22, by means of rivets or other suitable fastening means. A

The upper end of the collar 32 1s turned back inwardly upon itself to form an annular recess which receives a split ring 35, such ring being of spring metal arranged to maintain a constant expanding pressure on the upper end of the collar 32. It is to be understood that thisring 35 may be attached or secured to the upper end of the sleeve, in any manner as will occur to those skilled in the art.

As the drill is being assembled and the inner barrel is passing downwardly in the outer barrel (as shown in Fig.I l), it will be noted that the upper end of the collar 33 is in contact with the inside of the upset portion of the outer barrel 10, and that when the inner barrel is connected to the cutter head, as shown in Fig. 3, the upper end of the collar 32, having passed below the upset portion of the outer barrel, is expanded outwardly against the inner wall of the outer barrel roper. panded position, t e flush iuid will be caused to entirely pass through the openings 23 in the head 22 and maximum efficiency attained.

What I claim is:

l. In combination, a core drill having an linner and an outer barrel forming a passage therebetween for circulating duid, a valve on the upper end of said inner barrel having discharge nozzles therefor, a head on said inner barrel having discharge openings receiving said discharge nozzles, and means for closingv the space between said head and the outer barrel.

2. In combination, a core drill having an inner and an outer barrel forming a passage therebetween for circulating fliud, a valve on the upper end of said inner barrel having When in this eX- discharge nozzles therefor, a head on said inner barrel having discharge openings receiving said discharge nozzles, and yielding means mounted 0n said head, for closing the space between said head and the outer barrel.

3. In combination, a core drill having an inner and an outer barrel forming a passage therebetween for circulating ui a valve on the upper end of said inner barrel having downwardly extending discharge nozzles therefor, a head on said inner barrel having discharge openings receiving said discharge nozzles, and means for closing the space between said head and the outer barrel..

4. In combination, a core drill having an inner and an outer barrel forming a passage therebetween for circulating fluid, a valve on the upper end of said inner barrel having downwardly extending discharge nozzles therefor, a head on said inner barrel having discharge openings receiving saiddischarge nozzles, and means for closing the space between said head and the outer barrel-, said means consisting of a ieldable collar on said head, and means or expanding said collar.

5. In combination, a core drill having an inner and an outer barrel forming a passage therebetween for circulating fuid, a valve on the upper end of said inner barrel having downwardly extending discharge nozzles therefor, a head on said inner barrel having discharge openings receiving said discharge nozzles, and means for closing the space between said head and the outer barrel,-said means consisting of a yieldable collar on said head, and a split spring ring secured to the upper end of said collar. 6. In combination, a core drill having an inner and an outer barrel forming an annular passage therebetween for circulating duid, a head on said inner barrel having a discharge opening therein with downwardly conver ing walls, a valve on said inner barrel, a ownwardly extending discharge nozzle on said valve extending into the discharge opening in said head, and yieldable means on said head extending into engagement with the outer barrel.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this l0 day of August, 1927.

FLOYD C. MERRITT. 

